Many consumer and over the counter drug products are packaged in small hand held containers, with removable closure caps to retain the freshness of the product, or of the active ingredients in the case of over-the-counter drug products, between uses of the product. As one example, topically applied medicated lip balm is often packaged in a hand-held cylindrical hollow tube with a removable closure cap. In a typical construction, the lip balm is embodied in a wax-like substance and is elevated through an opening in the upper end of the tube by rotating a screw thread element which extends into the bottom of the wax-like substance. The screw thread element is typically rotated by means of a knurled wheel extending from the bottom of the tube. A removable closure cap usually fits snugly over the opening of the tube.
In the case of treatment products imbedded in a wax-like carrier substance as described above, a portion of the wax-like substance normally remains protruding about one-eighth inch from the top of the container after use. Thus, the cap must provide a clearance between the inner surface of the top of the cap and the upper rim or opening of the cylindrical tube so as not to contact and depress the waxy substance under normal conditions when the cap is closed over the open end of the tube.
Many prior caps provided with tube-like and other containers for topically applied consumer or medicinal products are completely removable when the contents of the container are to be used. Tubes previously in use would often be held in one hand while the cap would be grasped in the fingers of the other hand, thus requiring two hands to open the container. Often a product such as a medicated lip balm is applied by a user when outside on a cold or raw day, where only one hand, and more than likely a gloved hand, may be available to reach the container for the product, and then to open the container. It is inconvenient to use prior products under such conditions, since two hands are required to hold and open these containers.
Another disadvantage of containers where the cap is completely removable is that the cap can become easily misplaced, soiled or lost after it is removed from the container. This is true particularly when attempting to apply a medicated lip balm on those occasions when both hands are not totally free.
A further disadvantage of containers of the type described with removable closure caps is that if not designed properly, the cap can become dislodged from the container while the product is still in the users pocket or handbag, thereby potentially soiling the clothes or a handbag of the user, or potentially contaminating the remaining product within the container.
The closure cap of the prior containers described above is not designed for one hand or thumb pressure opening. Thus, there is a need for a closure cap for a product container which is designed to be operated with thumb pressure, using the thumb of the same hand that is holding the container. There is further a need for such a closure cap which will not become lost, dropped or soiled after being lifted to open the container, or which will not accidentally become dislodged while in the pocket or handbag of a user, potentially contaminating the product within the tube.